The present invention relates to a mounting (also referred to as assembling) device for mounting and removing (also referred to as disassembling) a fuel injector, in particular a high-pressure direct injector, into and from a mounting bore in a cylinder head of an internal combustion engine. Fuel is injected directly into the combustion chamber of the internal combustion engine through this high-pressure direct injector.
An assembling device having a main body at least partially surrounding the fuel injector is described in German Patent Application No. 197 05 990 A1, collar section directed inward is formed at a first end of the main body, and a collar section directed outward is formed at a second end of the main body, opposite the first end. While the collar section directed radially inward can be inserted into a groove of the fuel injector, the collar section directed outward protrudes outward from the mounting opening of the fuel injector. An appropriate tool, for example, an assembly iron, can engage the mounting hole of the cylinder head in order to lift the assembling device together with the fuel injector from the mounting hole.
This conventional assembling device is not suitable for transmitting a hold-down force to the fuel injector to counteract the combustion pressure in the combustion chamber of the internal combustion engine. Therefore, the fuel injector is held down via a separate hold-down device or the fuel injector is only secured in the mounting hole by friction. The collar section protruding inward can, however, transmit a pressure force to the fuel injector to press the fuel injector into the mounting hole. For this purpose, the collar section protruding inward engages in a corresponding groove in the fuel injector. The disadvantage, however, is that this pressure force does not act at the center and symmetrically with the central axis of the fuel injector, but in a rather one-sided manner. Furthermore, ease of handling of the assembling device when inserting the fuel injector is subject to improvement.
U.S. Pat. No. 4,561,159 describes a disassembling device for a diesel injection nozzle. An end area of the fuel injector opposite the spray orifice can be inserted at the side into a slit in the disassembling device. The disassembling device is not inserted into the mounting bore of the cylinder head and it does not remain in the mounting bore when assembled. The disassembling device described in U.S. Pat. No. 4,561,159 is instead a tool extension that is attached to the fuel injector before disassembling the fuel injector. No hold-down force is transmitted to the fuel injector. Connecting the disassembling device to the fuel injector is a relatively complicated process.
The assembling device according to the present invention having the characterizing features of claim 1 advantage over the conventional devices that the two contact elements apply a centered and symmetrical hold-down force to the fuel injector, so that an oblique position or tipping of the fuel injector is avoided. The locking connection between the assembling device and the fuel injector considerably improves handling when inserting the fuel injector into the assembling device. The fuel injector is inserted into the assembling device axially, rather than laterally, which can be better controlled, especially in partially or fully automated production.
If at least two diametrically opposite contact sections are provided, the hold-down force, as well as the disassembling force, are introduced, to a considerable degree, centrally and symmetrically to the central axis of the fuel injector.
The locking projections formed on the fuel injector have, for example, a taper facing away from the hold-down surfaces. The taper helps the locking projections engage the locking recesses provided on the contact elements.
The assembling device is guided, for example, into the mounting hole with a slight clearance in order to ensure accurate axial alignment of the assembling device with respect to the mounting hole even if the internal combustion engine installed in a vehicle, for example, is subjected to a jarring motion.
A recess for the connecting plug of the fuel injector is advantageously provided between the contact elements, so that the connecting plug of a fuel injector mounted on the assembling device is arranged between the contact elements.
The assembling device can be economically manufactured by deep drawing from a metal sheet.